Footage showing the apparent execution of four men loyal to President Bashar Assad and piles of bodies of government militiamen in a police station suggest that rebels are using the same tactics for which the Syrian leader's own forces have been condemned.

A video posted on YouTube shows four purported militiamen being led into a crowded yard before a prolonged barrage of gunfire is unleashed as people chant "God is Greater." As the smoke clears, a crumpled pile of bodies can be seen by a wall.

The execution appeared to have been carried out in a schoolyard at an undisclosed location in Aleppo. It took place as Assad's forces attacked residential neighborhoods with artillery and from the air to try to drive out the rebels.

In the video, which could not be independently confirmed, the men were identified as members of the pro-Assad "shabbiha" militia from the Berri family. At least two of them were in their underwear as they were led down a flight of stairs and lined up in front of a wall.

Gunmen firing on them with semi-automatic rifles continued shooting after the men had fallen to the ground, their bodies piled one on top of another.

The shabbiha (ghosts), have been at the forefront of the crackdown on the 17-month revolt against the ruling Assad family, who are members of the Alawite sect, an offshoot of Shi'ite Islam.

With secret police support the militia, originally all Alawites, expanded after the uprising erupted in March last year to encompass Sunni recruits drawn mainly from the northern city of Aleppo and the eastern province of Deir al-Zor.

Another video showed rebels gloating triumphantly on Tuesday after taking over a police station in the town of Nayrab southeast of Aleppo.

"Come and see the carcasses that die for the sake of Assad," one rebel says before the camera goes into the police station and shows at least 15 bodies in the garden and inside the building, which is riddled with bullet holes and partly burnt.

One rebel points his rifle at the body of the commander of the station, identified as Lieutenant Ahmad Khatib, and fires a bullet that blows the dead Khatib's head off.

"I spit on you, and on the tyrant Bashar Assad," the unidentified fighter said.

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